Insulated ground electrical receptacles are specially constructed to provide a "clean" ground for computer equipment and other equipment which may be adversely affected by spurious electromagnetic radiation. The offending electrical signals are thought to be transmitted through the air and through conductors connected to the building ground. Insulated ground receptacles impose an insulator between the equipment ground and the building ground structure to keep electrical noise from passing from the building ground to the equipment grounded. The insulator eliminates the redundant grounding regular receptacles provide and may be thought of as lowering the degree of safety. This may not be tolerable in critical care areas of the hospital such as ICU's and operating rooms. This study will investigate the noise advantages and the safety disadvantages of insulated ground receptacles.